Electromagnetic relay and a method for its production

ABSTRACT

An electromagnetic system having a coil (8), a yoke (10) and an armature (11) is arranged in the upper region of the cap in the relay having a housing cap (1) which is closed at the top, while a contact system (5, 6, 7) is mounted in the lower region in the vicinity of the connection side of the relay. Coil connecting elements (20) are embedded in each case in one side wall of the cap (1), for the connection of the coil winding, in such a manner that their ends open on the top of the cap in each case in a depression (18) which is open to the exterior. During the assembly of the magnet system, winding supporting elements (15), which are provided in each case on the coil former, are inserted into these depressions. The ends of the winding supporting elements (15) and of the coil connecting elements (20) are then be electrically conductively connected from the exterior by soldering or using a conductive adhesive. This results in a space-saving connection, which is nevertheless insulated with respect to the ferromagnetic parts of the magnetic system and the contact elements, between the winding ends of the coil (8) and the corresponding connecting pins (20a) on the bottom of the relay.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an electromagnetic relay having the followingfeatures:

a housing has a cap with an essentially closed top, closed side wallsand an open bottom, which can be closed by a bottom part.

arranged in the housing are a contact system, with contact connectingelements which are guided out of the housing, and a magnet system whosecoil is located adjacent to the closed top of the cap, and

the winding ends of the coil are connected in each case to supportingelements, which are anchored in a coil former and, for their part, areelectrically conductively connected to coil connecting elements whichare guided out through the bottom.

In addition, the invention relates to a production method for such arelay.

2. Description of the Related Art

A relay having the above-described construction is disclosed, forexample, by German published application 38 35 105. A narrowconstruction is achieved by the disclosed arrangement of the coil abovethe contact system in the closed upper region of the housing. As aresult of the arrangement of the contact elements in the vicinity of theconnection side in the lower part of the housing, short electricalconnections are also ensured between the contacts and the associatedconnecting pins, which not only permits a saving in material andmanufacturing steps, but also provides advantages with respect to heatdissipation and the insulation between the contact elements and themagnet system. This structural shape is therefore preferably used forheavy-current and mains relays.

As a result of the arrangement of the coil in the upper region of thehousing, it is, however, necessary to guide the coil connecting elementsvia a relatively long path up to the connection side of the relay, itbeing necessary, however, to ensure the insulation to the PG,4ferromagnetic circuit parts of the magnet system and to the contactelements. Especially when the relay is used at relatively high voltages,this insulation requires a notinconsiderable space in the housing,either in the form of corresponding projections of the coil former or inthe form of additional insulating parts.

SUMMARY OF THE INVENTION

The object of the invention is to specify a relay of the type mentionedinitially and a production method for this relay, in which a simple andspace-saving connection of the winding ends of the coil to theconnection side of the relay is made possible while retaining the basicconstruction. In particular, it is intended in this case to ensure theinsulation between the coil connecting elements and the magneticcircuit, as well as the contact elements, without any additional spacerequirements.

In order to achieve this object, a relay according to the invention hasthe following additional features:

the coil connecting elements are guided in insulated fashion in eachcase in a side wall of the cap, from the bottom as far as the region ofthe top of the cap, and open in a depression of the cap top, which isopen outwards,

the supporting elements of the coil former, which are electricallyconnected to the coil, are guided in insertion openings with respect tothe cap top and likewise open in each case in one of the depressions,and

in each depression, the respective end of a supporting element isconductively connected to the end of a coil connecting element.

In the relay according to the invention, the coil connecting elementsare thus guided in an insulated manner directly in the wall of the cap,preferably by being embedded in the side wall. In consequence, withinthe housing space, there is no need for space for these coil connectingelements themselves nor for additional insulating walls. The spacerequirement is thus determined just by the extent of the magnet systemand of the contact system.

The conductive connection between the ends of the respective supportingelement and of the associated coil connecting element can basically beproduced in different ways using standard methods. Welded connections orsoldered connections come into consideration in this case, if thestructure can be designed such that the ends to be connected areaccessible for welding electrodes or for soldering devices, and, ifnecessary, the resistance to the soldering temperature is ensured in thevicinity of the soldering point. However, a connection by means of aconductive adhesive is particularly advantageous, which can beincorporated into the respective depression and sets at a relatively lowtemperature. In order to ensure the insulation of the connecting pointto the exterior, an insulating material layer, which closes off thedepression to the exterior, is preferably applied to the connectingpoint or to the conductive adhesive.

A preferred method for producing the relay comprises the followingsteps:

the cap is formed with the coil connecting elements embedded in at leastone side wall, with depressions on the cap top in the region of the endsof the coil connecting elements and with insertion openings in theregion of the depressions,

the magnet system and the contact system are inserted into the open cap,supporting elements embedded in the coil former being inserted with freeends into the insertion openings in the cap, and

in each case one supporting element is conductively connected to onecoil connecting element in the depressions on the cap top.

If it is intended to close the housing off in a waterproof manner, it isadvantageous, before producing the conductive connection in thedepressions, to seal the bottom of the cap with potting compound, itbeing possible to use the insertion openings in the cap as ventilationholes until the potting compound sets. The supporting elements and thecoil connecting elements can in each case be conductively connected, andthe insertion openings at the same time closed in a sealed manner, bythe insertion of conductive adhesive into the depressions. Thesedepressions can then be additionally sealed, and the conductiveconnections insulated to the exterior, by the application of insulatingmaterial to the conductive connection in the depressions.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in more detail in the following text, makinguse of exemplary embodiments in conjunction with the drawing, in which:

FIGS. 1 and 2 show a relay designed according to the invention in twosectional views, the left half of FIG. 2 showing a section IIL--IIL andthe right half a section IIR--IIR from FIG. 1, and

FIG. 3 shows a completely assembled relay in a perspective view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The relay shown in FIGS. 1 to 3 has a housing which consists of a cap 1having a closed top 2 and side walls 3, which are closed all round, anda contact support 5, which is inserted as a base into the open bottom 4of the cap 1. Contact elements 6 and 7, which are mounted on the contactsupport 5, are mounted with their connecting elements 6a and 7a in thelower region of the housing, adjacent to the bottom. A magnet system,having a coil winding 8, a core 9, a yoke 10 and an armature 11, isarranged in the top region, adjacent to the closed top 2 of the cap, thearmature operating the contact element 7 via an operating element 12.The construction and operation of the relay beyond this areintrinsically not a subject matter of this application and are thereforealso not described in detail.

The coil winding 8 is seated on a coil former 13, in whose flange 14 twowire-shaped supporting elements 15 and 16 are anchored for winding andcontacting the ends of the windings. These supporting elements 15 and 16are guided with their free ends in each case through an insertionopening 17 into one of two depressions 18 on the top of the cap 1. Thesedepressions 18 are formed in the top 2 of the cap and are initially openoutwards, but are connected to the housing interior only via theinsertion opening 17.

In addition, two coil connecting elements 20, each of which has aconnecting pin 20a, which is guided out towards the bottom, and aconnecting end 20b, which opens in each case into a depression 18 on thecap top, are embedded in one of the side walls 3 or in rib-likethickenings 19 in two corners of the side wall.

The depressions 18 are filled from the exterior with conductive adhesive21 which in each case electrically conductively connects the supportingelements 15 and the coil connecting elements 20. An insulating materiallayer 22, which closes off and insulates the housing at the top, isapplied over the conductive adhesive 21.

During assembly of the relay, the magnet system is initially insertedinto the cap 1 and is mounted, therein the supporting elements 15 beinginserted through the insertion openings 17. The housing is closed off atthe bottom by the use of the contact system with the support 5. Thehousing is sealed by the application of a layer of potting compound 23,the insertion openings 17 acting as ventilation holes which permitpressure equalization while the potting compound 23 is setting. Theconductive adhesive 21 is thereafter inserted into the depressions 18,the depressions then being closed off to the exterior by the insertionof the insulating material layer 22.

FIG. 3 shows a complete relay in a perspective view. The depressions 18,in which contact has been made with the coil connections in the mannerpreviously described, and which are provided in the top and are sealedwith the insulating material layer 22, can be seen on the cap 1.

Although other modifications and changes may be suggested by thoseskilled in the art, it is the intention of the inventor to embody withinthe patent warranted hereon all changes and modifications as reasonablyand properly come within the scope of his contribution to the art.

I claim:
 1. An electromagnetic relay, comprising:a housing including acap with a substantially closed top, closed side walls and an openbottom, said housing including a bottom part mounted to close said openbottom of said cap, a contact system in said housing and having contactconnecting elements guided out of said housing, a magnet system having acoil located adjacent to the closed top of said cap, supporting elementsconnected to winding ends of said coil a coil former in which saidsupporting elements are anchored coil connecting elements electricallyconnected to said supporting elements, said coil connecting elementsbeing guided in each case in insulated fashion in said closed side wallsof said cap from the bottom as far as the region of the top of said cap,and extending into a depression in the top of said cap which is openoutwards, said supporting elements of said coil former being guided ininsertion openings with respect to the top of said cap and likewise openin each case in one of said depressions, and a conductive connection ineach of said depressions between the respective end of said supportingelements and an end of said coil connecting element.
 2. The relay asclaimed in claim 1, wherein said coil connecting elements are in eachcase embedded in said side walls of said cap.
 3. The relay as claimed inclaim 1, wherein said conductive connection between the ends of saidrespective supporting element and of said coil connecting element is aconductive adhesive which at least partially fills said depression. 4.The relay as claimed in claim 1, further comprising:a layer ofinsulating material sealing said depressions, said layer of insulatingmaterial covering said conductive connection between the supportingelement (15) and the coil connecting element.
 5. A method for producinga relay, having the following steps:forming a cap with coil connectingelements embedded in at least one side wall, with depressions on a topof the cap in a region of ends of the coil connecting elements and withinsertion openings in a region of the depressions, inserting a magnetsystem and a contact system into the cap, inserting supporting elementsembedded in the coil former with free ends into the insertion openings nthe cap, and conductively connecting in each case one supporting elementto one coil connecting element in the depressions on the top of the cap.6. The method as claimed in claim 5, further comprising the stepof:before said step of conductively connecting in the depressions,sealing the bottom of the cap with potting compound, the insertionopenings in the cap being used as ventilation holes until the pottingcompound sets.
 7. The method as claimed in claim 5, wherein said step ofconductively connecting the supporting elements and the coil connectingelements includes insertion of conductive adhesive into the depressions,which also closes the inserting openings in a sealed manner.
 8. Themethod as claimed in claim 5, further comprising the step of:closing offthe depressions at the top by the application of an insulating materiallayer to the conductive connections.